The request is for time to collect data from two protein capsids. The first is a virus-like particle (VLP) of HK97, a bacteriophage, assembled in an E. coli expression system. We currently have a 5 E electron density map of this T=7 particle and seek to collect data to 3.5 E. The second project is to collect data from a mutant of cowpea mosaic virus that carries a "cysteine noose" on its surface.